The present invention relates in general to containers for bulk material, and more particularly to a container for bulk material having a follower constantly engaging the upper surface of the bulk material as the bulk material is removed from the container.
Heretofore, bulk material containers employed flexible followers for cleaning the interior surfaces of containers for bulk material and for applying a downward force on the bulk material. Such bulk material containers are disclosed in the patent to Coleman, U.S. Pat. No. 3,781,942, issued on Jan. 1, 1974, for Follower For Material Containers.
To fill a material container having a flexible follower, it was the practice to fill the container by discharging viscous or liquid material into the container below the flexible follower and at the axial center of the bottom wall of the container so that the flexible follower would rise, as the viscous material is filling the container, in a horizontal position. More specifically this practice was carried out to maintain the flexible follower in a horizontal plane perpendicular to the cylindrical axis of the container, as distinguished from being tilted or at an acute angle relative to the cylindrical axis of the container.
It has been desirable to fill the container with bulk material by discharging material into the container through the top wall of the container. Previously, the material container had to be either inverted or have the bulk material pumped in under the diaphragm.
In the aforementioned patent to Coleman, U.S. Pat. No. 3,781,942, there is disclosed an arrangement for introducing bulk material through the access opening at the top of the container through an inlet conduit extending near the bottom of the container. The diaphragm of the flexible follower was formed with an opening through which the inlet conduit passed. The opening was shaped so that the walls surrounding the opening received the inlet conduit in a snug manner. The container may be filled in the manner just described and the material may be withdrawn from the container from an outlet opening at the bottom of the container or through a sump pump connection. Additionally, the bulk material may be removed through the access opening.
Heretofore, bulk material containers suitable for viscous material employed a flexible bag liner in which the viscous material was contained while disposed in the material container. A dip tube passed through the top wall of the material container and was disposed in the flexible bag liner for discharging viscous material into the flexible bag liner. Such a bulk material container is disclosed in the patent to Coleman, U.S. Pat. No. 3,590,888, issued on July 6, 1971, for Composite Container And Method Of Handling Fluent Materials.